Solar bumps into grid issues downtown

Updated 6:26 pm, Friday, October 12, 2012

How solar panels convert the sun's energy into electricity.

Media: San Antonio Express-News

When Lake|Flato Architects decided to add a 10-kilowatt solar array to its building, the company sailed through CPS Energy's rebate application process. The architecture firm hoped the size of the array would allow it to send electricity back into the grid on days the office was closed.

It was only after the firm had installed a $40,000 system, around $14,000 after CPS and federal rebates, that employees said they heard some ominous words from a CPS inspector: “I have made a huge mistake.”

Lake|Flato had inadvertently uncovered a quirk in the burgeoning effort to add more solar panels downtown. You can install solar, but if you're downtown, you can't produce excess power and sell it back into the grid because of a risk that resulting surges could cause power outages.

Lake|Flato worked with CPS before installing anything — providing its address and CPS account number — to make sure the firm would qualify for its solar rebate. A CPS inspector pre-approved the project but somehow didn't realize the company was downtown until coming to the property for a final inspection.

Photo: Darren Abate, Darren Abate/For The Express-New

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A ten-kilowatt solar array is seen at lower-right, photographed Monday, Oct. 8, 2012, at the offices of Lake|Flato Architects in San Antonio.

A ten-kilowatt solar array is seen at lower-right, photographed Monday, Oct. 8, 2012, at the offices of Lake|Flato Architects in San Antonio.

Photo: Darren Abate, Darren Abate/For The Express-New

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A ten-kilowatt solar array, photographed Monday, Oct. 8, 2012, at the offices of Lake|Flato Architects in San Antonio.

A ten-kilowatt solar array, photographed Monday, Oct. 8, 2012, at the offices of Lake|Flato Architects in San Antonio.

Photo: Darren Abate, Darren Abate/For The Express-New

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A ten-kilowatt solar array, photographed Monday, Oct. 8, 2012, at the offices of Lake|Flato Architects in San Antonio.

A ten-kilowatt solar array, photographed Monday, Oct. 8, 2012, at the offices of Lake|Flato Architects in San Antonio.

Photo: Darren Abate, Darren Abate/For The Express-New

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A ten-kilowatt solar array at lower right, photographed Monday, Oct. 8, 2012, at the offices of Lake|Flato Architects in San Antonio.

A ten-kilowatt solar array at lower right, photographed Monday, Oct. 8, 2012, at the offices of Lake|Flato Architects in San Antonio.

Photo: Darren Abate, Darren Abate/For The Express-New

Solar bumps into grid issues downtown

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“It was only when CPS came for the inspection that this came up,” said Heather Holdridge with Lake|Flato. “I don't know how he only realized that (this) was downtown at this moment.”

It turns out that a glitch in the CPS computer system wasn't flagging downtown addresses as being part of the downtown electric grid.

Only a few buildings have solar arrays in the downtown grid — generally defined by CPS as the area within Interstate 10, Interstate 35 and U.S. 281 — so this is a relatively new issue, said Lanny Sinkin, executive director of the nonprofit Solar San Antonio.

Across the street from Lake|Flato, the recently renovated 1930s-era Hipolito F. Garcia Federal Building & U.S. Courthouse bumped into the same issue with its 50-kilowatt array.

Christine Patmon, public relations manager at CPS, said downtown's electrical grid is different than the grid elsewhere in the city.

It has multiple circuits to make sure places like the Police Department and City Hall always have power.

“The situation with the downtown grid is that it has multiple backup systems,” Patmon said. “A system that produces more than what the customer is using can possibly create a surge. That impacts the downtown grid and the customer's system as well.”

Later it was allowed to plug into the grid, at least, and could keep the rebate.

“The initiatives are there but the implementation isn't. If there's an infrastructure issue, I understand it,” Holdridge said. “Why did it get approved in the first place?”

To prevent their solar arrays from feeding electricity back into the grid, both Lake|Flato and the Garcia building have to shut down their solar panels if it looks like they might start producing excess energy.

The GSA still wants to install solar panels on its garage across the street from the Garcia building but hasn't been able to do so because the panels would create excess energy. In contrast with Lake|Flato, it found out about the restrictions before installation.

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“GSA really explored all options with CPS including feeding to the grid or feeding to the Garcia building, none of which have been agreeable,” Mayberry said. Sinkin said the GSA can't run the excess power from the garage to the Garcia building because it would have to cross the street, making the GSA a “distributor” of electricity. Only CPS can distribute electricity in San Antonio, he said.

Patmon said the downtown address issue has been fixed in CPS' computer system. And Lake|Flato and others who install solar still are eligible for the solar rebate program.

CPS also is updating its manual to make clear that downtown solar users can't feed into the system. It also will recommend that no one located downtown install solar above a building's minimum load and that they each install blockers to prevent a system from feeding electricity back into the grid.

“It does not mean that commercial buildings downtown can't install solar,” Sinkin said. “It just means it has to have that cutoff switch.”

He said that as a downtown-only issue, this shouldn't impede efforts to add solar across the San Antonio area. “The normal homeowner doesn't have to worry about any of this.”

And because solar remains pricey and the payback can take a long time, it's rare for buildings to have enough panels produce excess power.

“We don't recommend that anyone try to produce more power than they use,” Patmon said. “The return on investment just isn't worth it.”

In parts of the state with privately owned utilities, Public Utility Commission of Texas has rules requiring utilities to provide net metering if a customer requests it. But Terry Hadley, spokesman with the PUC, said those rules don't apply to municipal utilities such as CPS.

“It surprises me,” he said. “CPS has seemed to be out in front in encouraging solar generation.”

CPS this summer signed a landmark deal for the construction of five solar plants around the state, providing CPS with access to 400 megawatts of power. The deal will bring to San Antonio 805 jobs paying an average of $47,000 a year — a payroll of about $40 million.

And CPS rebates up to $25,000 for residential and $100,000 for commercial solar installations.

The CPS rebate covers about $2 of the $4-per-watt cost of the system, Holdridge said. With a federal rebate of 30 percent, Lake|Flato figured it would take less than five years for the solar project to pay for itself.

Not being able to net meter on the weekends may throw that off slightly, Holdridge said. But for the firm, which is known for its environmentally sensitive design, it's not about getting paid for feeding into the system.

“We went into this as a demonstration project. It was supposed to be a model of how our buildings ought to be,” Holdridge said. “We try to walk and bike to work, and we think buildings should be independent when they can be. Now it's serving as this cautionary tale.”

Express-News archives contributed to this report.

jhiller@express-news.net

Correction: At no point did CPS Energy tell Lake|Flato Architects it would lose its solar rebate. A story on Friday’s page A1 of the Express-News and on mySA.com incorrectly said the firm was told it would.